In the past, biodegradable filter media comprising a water-soluble component have been used to form cigarette filters. Such filters generally comprise cellulose acetate fibers and a biodegradable, water-soluble additive. Preferably the additives are starch, starch derivatives, or dextrins. Such filters are disclosed in European Patent No. 609284 (World Patent No. 9307771).
Blends of destructurized ("gelatinized") starches and various synthetic polymers are disclosed in U.S. Pat. No. 5,095,054.